Distributing device



Aug. 13, 1929.

T. F. PIGOTT DISTRIBUTING DEVICE v Filed y 17. 1928 INVENTOR EOMAS F. R GOTT m ATTORNE Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE."

THOMAS F. PIGOTT, OF BROOKLYN, NEW YORK, ASSIGNOR TO RILEY STOKER GOR- IPORATION, O11 WORCESTER, MASSACHUSETTS, A. CORPORATION OF MASSACHU- DISTRIBUTING DEVICE.

Application filed May 17, 1928. Serial No. 278,590.

This invention relates to distributing devices, and more particularly to a construction which is arranged to distribute pulverized material uniformly to a pair of conduits.

In transporting pulverized material on a fluid current through a pipe line, it is found that the material and particularly the coarser particles thereof tend to segregate in lo the bends because of the action of centrifugal force. WVhen therefore the pipe line is split into a pair of branch lines, great difiiculty is experienced in dividing the stream equally between the branches, since centrif- 15 ugal force tends to throw the majority of the material and particularly the coarser particles thereof into one branch, and the other branch receives but little. Such difficulties have frequently arisen in the burning of pulverized coal. The pulverized coal is taken from a storage bin or directly from one or more pulverizers and transported through a conduit on a current of air. In many installations the coal stream is divided and sent through branch pipes, each leading to a separate burner. It is necessary for ellicient operation that each of the burners receive the same quantity and fineness of coal, but this result is difficult to attain since there are almost invariably bends in the pipe line which produce segregation of the coal anterior to the division point. Moreover the problem is rendered even more difiicult be cause the space in front of the furnace is usually limited and the piping must be made as simple and free from complications as possible.

Various constructions have been proposed in the past to overcome these difficulties, but they have been open to seriousobjections. For example, certain prior arrangements have involved devices mounted within the pipe line and so shaped as to restrict the flow of material therethrough. Such restrictions are undesirable, since they increase the back pressure and hence the power required to drive the fan and since they slow up the rate of flow through the pipe and thus cause the pulverized material to separate from the fluid current and become deposited in the pipe.

If the discharge pipes are so arranged relative to the inlet pipe that the plane of the bend of the supply pipe isat right angles to the plane of the discharge conduits, i. e., the plane defined by their center lines, then no serious problem is presented, since the material Will tend to divide evenly between the two discharge pipes. If, on the other hand, these planes are at less than a right angle, then centrifugal force acting upon the material tends to throw it towards one of the discharge pipes.

It is accordingly one object of my invention to provide a construction which will ensure a uniform distribution of pulverized material from a supply conduit to a pair of branch conduits, and particularly where the plane of the bend of the supply conduit is at less than a right angle to the plane of the discharge conduits,

A further object of my invention is to provide a distributing device which will permit the material to flow freely thereby without restriction, and which will be simple and inexpensive to manufacture and install.

With these and other objects in view, as will be apparent to those skilled in the art,

my invention resides in the combination of 1 parts set forth in the specification and covered by the claims appended hereto.

In accordance with my invention, I pro vide a supply conduit arranged to deliver a stream of pulverized material on a fluid current to a pair of discharge conduits leading to points of use or deposit. In order to ensure an equal division of the pulverized material between the discharge conduits, I mount a partition plate in the supply conduit with one edge arranged to split the stream through the center of any segregation which may be present therein, and I so arrange these parts that the stream on one side of the partition passes into one of the discharge con duits and the stream on the other side of the partition passes into the other discharge conduit. The supply conduit may have a bend therein which causes the pulverized material to segregate by the action of centrifugal force, and the partition may be formed by a plate twisted into the shape of a helix with one edge in the plane of the bend in the supply conduit and with the other edge perpendicular to the plane of the discharge conduits.

Referringto the drawings illustrating one embodiment of my invention, and in which like reference numeralsindicate like parts,

Fig. 1 is a front elevation of an installation to'which my invention has been applied, parts being broken away for clearness of illustration;

Fig. 2 is an enlarged View in section of a portion of Fig. 1, the section being taken through the center of the piping;

Fig. 3 is a plan view of a part of the construction, the view being taken on the line 3-3 of Fig. 2;

Fig. 4 is a perspective view of the partition plate shown in the preceding figures;

Fig. 5 is a front elevation of a modified form of the invention, parts being broken away for clearness of illustration;

Fig. 6 is an enlarged plan view of the construction shown in Fig. 5, parts being broken away; and

Fig. 7 is a perspective view of the partition plate shown in Figs. 5 and 6.

The embodiment of my invention illustrated in the drawings comprises a system for distributing pulverized fuel to furnace burners for combustion.

A pair of pulverized fuel burners 10 and 11 are shown mounted on the front walls of two adjacent furnaces 13 and 14 respectively. In some cases both burners may be mountedupon the same furnace, and this Will in no way affect the operation of the present invention. The burners may be of any suitable type for use in connection with pulverized fuel, such as, for example, the

' burner shown in the patent to Couch No.

lVhilefuel may be supplied to the burners from a suitable storage bin, I have shown the furnaces as fired directly from a pair of pulverizers 16 and 17 of the unit type. These pulverizers may be of any construction which is adapted to pulverize the fuel finely and deliver it on a current of air. The patent to Andrews N 0. 1,646,720 describes one suitable apparatus. The pulverizers 16 and 17 are provided with hoppers 19 and 20 respectively for the coarse fuel, and are driven by electric motors 22 and 23.

vOrdinarily one pulverizer is of suflicient capacity by itself to operate both furnaces at their normal rating, and the other pulverizer may therefore be maintained as a standby. In order that eithermachine may be used as desired, I provide interconnecting piping between the pulverizers and burners. A pipe 25 leads from pulverizer 16, and a pipe 26 leads from pulverizer 17, both pipes being joined to a Y connection 28. A short vertical pipe 30 leads from the Y fitting 28 to a second Yfitting32 which forms a pair of discharge conduits, and pipes 34 and 35 connect this second Y to the burners 10 and 11 respectively. Suitable cutoff valves 37 and38'are provided in the pipes 25 and 26 respectively close to the Yfitting 28. These valves are preferably of the quarter turn type well-known in the art, and permit the pipe to be closed off from either of the pulverizers which may be standing idle.

At times it may be desirable to operate one only of the furnaces, and in order that this may be done, I provide a blade 40 (Fig. 2) which is pivotally mounted within the Y litting 32 about an axis perpendicular to the plane of the fitting. This blade is thus between the discharge conduits and may be adjusted by means of a handle 41 so as to throw the entire fuel stream into either burner desired. As a practical matter, it is diflicult to make such a pivoted valve perfectly tight, and for this reason I preferably use cut-oil valves 45 and 46 in the pipes 34; and 35 respectively. These valves are mounted close to the Y fitting 32 and permit the pipe leading to either burner desired to be tightly closed.

The construction as so far described is subject to certain serious disadvantages which are overcome by my invention. Suppose pulverizer 17 is supplying fuel to both burners, pulverizer 16 is shut down, and valve 37 is accordingly closed. Because of the action of centrifugal force, the fuel will tend to separate from the air as it passes around the bends in pipe 26 and Y fitting 28, and most of the fuel will flow downwardly along the left side of pipe 30 in Fig. 1 and. thus go to burner 10. It is impossible to entirely obviate this trouble by an adjustment of the blade 40, since the coarse particles of fuel segregate more than the fine particles. \Vhile blade 40 might possibly be adjusted to equalize the quantities of fuel passing to the burners, such adjustment could not prevent most of the coarse fuel from passing to burner 10, which would result in poor and inefficient combustion in furnace 13.

In order to overcome these difiiculties. I provide a partition plate 50 within the pipe 30. This plate is mounted with its upper edge, which is first encountered by the fuel stream, in the plane of the bend in the supply conduit formed by pipe 26 and Y fitting 28, i. e., in the plane defined by the center line of the bend, so that the fuel stream is split evenly both as to quantity and fineness on each side of the plate. This plate is so shaped that its other or lower edge is in the plane of the blade 40, and preferably close to the upper edge of the blade. The partition 50 thus forms two separate fuel passages, each of which delivers fuel through a separate discharge conduit to its corresponding burner.

If desired the partition plate may be cast or otherwise formed integral with the pipe 30, or it may be made of a rectangleof sheet metal twisted into a helical shape as shown in Fig. at and welded to the pipe. In

either case the partition may be made comparatively thin, and it will therefore form no serious obstruction in the pipe.

In Figs. 5, 6, and 7 I have illustrated a slightly modified form of the invention which may be used when one pulverizer only is available to supply both burners. In such a case the supply pipe 55 leading from the pulverizer may have a bend therein in a different plane from that of the Y fitting 32, as shown in Fig. 6. The pipe 55 is connected directly to the short pipe 56, and the latter has in its interior a partition plate 58 similar to the plate 50, but twisted a smaller amount. The upper edge of the plate 58 is in the plane of the bend in pipe 55, and its lower edge is perpendicular to the plane of Y fitting 32. The fuel stream is thus divided evenly between the burners.

It will be noted that in both of the embodiments illustrated the bend in the supply conduit is in a plane at less than aright angle with the plane of the discharge conduits. By the plane of the discharge conduits, I mean the plane of the Y fitting 32, since it is apparent that the pipes 34: and 35, which are shown as located in this same plane, need not necessarily be so located. In Figs. 1 and 2 the supply conduits are in the same plane as the discharge conduits, so that the angle between the planes is zero, whereas in Figs. 5 and 6 the single supply conduit is in a plane at about forty five degrees with the plane of the discharge conduits.

The operation of my invention will now be apparent from the above disclosure. Coarse fuel, such as bituminous coal, is supplied to the hoppers 19 and 20 from a suitable supply, such as an overhead bunker, and the pulverizers are driven by their respective motors. In case it is desired to run both furnaces at high ratings, both pulverizers may be in use simultaneously, and the cut-off valves will all be open and the blade placed in its central position. If one pulverizer is shut down, its corresponding cut-off valve is closed. If one burner is shut down, the cut-ofi valve in its corresponding pipe is closed and the blade 40 thrown to that side. Whenever both burners are running, the blade 40 is left in its central position, and the plate splits the fuel stream evenly, sending half to each burner. The modification shown in Figs. 5, 6 and 7 operates in exactly the same manner except that only one pulverizer is used.

My invention thus provides a means for successfully interconnecting a pair of pulverizers with two burners by a simple piping system which is inexpensive and easy to install. If desired, the plping may all be in substantially the same plane as shown in Fig. 1, and thus it will require a minimum of space and be out of the way of coal larries or other equipment in front of the furnaces. The partition plate used for splitting the fuel is inexpensive to manufacture, and effective for the purpose intended. It permits free flow of fuel thereby, and causes a negligible amount of back pressure on the pulverizers.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is 1. A distributing device for pulverized material comprising a supply conduit for a stream of pulverized material borne on a fiuid current, a pair of discharge conduits leading from the supply conduit, the supply conduit having a bend therein leading into the discharge conduits which lies in a plane at less than a right angle with the plane of the discharge conduits, and a partition plate mounted in the supply conduit with the edge first encountered by the stream in the plane of said bend and with the other edge in a plane at right angles with the plane of the discharge conduits, whereby the pulverized material is divided equally between the dis charge conduits despite the segregation caused by centrifugal action in said bend.

2. A distributing device for pulverized material comprising a supply conduit, means for introducing into said conduit a stream of pulverized material borne on a fluid current, a pair of discharge conduits leading from the supply conduit, the supply conduit having a bend therein leading into the dis charge conduits which lies in a plane at less than a right angle with the plane of the discharge conduits, a partition plate mounted in the supply conduit with the edge first encountered by the stream in the plane of said bend and with the other edge in a plane at right angles with the plane of the discharge conduits, and a blade pivotally mounted between the discharge conduits about an axis perpendicular to the plane of the discharge conduits, whereby the pulverized material may be divided equally between the discharge conduits or the entire stream may be directed into either discharge conduit desired.

Signed at Brooklyn, New York, this 14th day of May, 1928.

M THOMAS F. PIGOTT. 

